Contoured wall heat exchanger

ABSTRACT

A heat exchanger and heat exchanger core are provided. The heat exchanger core includes a plurality of columnar passages extending between an inlet plenum of the heat exchanger core and an outlet plenum of the heat exchanger core, the columnar passages formed monolithically in a single fabrication process.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent claims priority as a divisional to U.S. Non-Provisionalapplication Ser. No. 15/816,499 (now U.S. Pat. No. 10,809,007), entitled“CONTOURED WALL HEAT EXCHANGER” which was filed on Nov. 17, 2017, and ishereby incorporated herein by reference in its entirety.

BACKGROUND

The field of the disclosure relates generally to gas turbine enginesand, more particularly, to a monolithically formed heat exchanger havingcontoured walls.

At least some known heat exchange devices use separate parallel platesand multiple pieces, such as orifice plates, to allow supply andextraction from assembled structures. The separate plates need to besealed by welding, brazing or by incorporating bolted and sealedflanges. Such separately assembled structures include a risk of leakage,leading to mixing of the working fluid and the cooling fluid or a lossof one or both of the fluids. Misassembly of the separate components ofthe heat exchanger may cause leakage problems. Additional maintenance isperformed to periodically verify the integrity of the heat exchangerfluid passages. Moreover, additional spare part inventory may benecessary for components of the heat exchanger that wear over time, suchas, but not limited to, seals. Heat exchanger packaging is typically noteasily adjustable for different applications due to the limitedconfigurations of heat exchanger components due to manufacturabilityconcerns. Additionally, it is difficult to channel the working fluid andthe cooling fluid to their respective heat exchanger fluid passages inin the core of counter-flow heat exchangers because of the complexgeometries involved in splitting the flow in the inlet plenum andjoining the flow in the outlet plenum.

BRIEF DESCRIPTION

In one embodiment, a heat exchanger core includes a plurality ofcolumnar passages extending between an inlet plenum of the heatexchanger core and an outlet plenum of the heat exchanger core, thecolumnar passages formed monolithically in a single fabrication process.

Optionally, the plurality of columnar passages each comprise a pair ofadjacent sidewalls separated by a flow gap. Also optionally, at leastone sidewall of the pair of adjacent sidewalls includes a plurality ofsurface features that extend into the flow gap. The plurality ofcolumnar passages may include a first set of first passages coupled inparallel flow communication and a second set of second passages coupledin parallel flow communication wherein the second set of second passagesis isolated from flow communication with the first set of firstpassages. A third set of third passages may be coupled in parallel flowcommunication, and the third set of third passages may be isolated fromflow communication with the first set of first passages and the secondset of second passages. Optionally, at least one of the first set offirst passages and the second set of second passages include individualcore flow passages that are sized differently than the remaining coreflow passages of the at least one of the first set of first passages andthe second set of second passages. The first set of first passages andthe second set of second passages may be coupled in thermal conductivecommunication with each other along a length of the first set of firstpassages and the second set of second passages between the inlet plenumof the heat exchanger core and the outlet plenum of the heat exchangercore. Optionally, the plurality of columnar passages includes aplurality of nonplanar sidewalls. Also optionally, the plurality ofcolumnar passages includes at least one of a plurality of flow guides, aplurality of dimples, a plurality of bumps, and a plurality of spikes.The heat exchanger core may further include a first heat exchangermanifold and a second heat exchanger manifold, wherein a transitionmember is formed on each end of at least one of the first heat exchangermanifold and the second heat exchanger manifold, and the transitionmember may include a plurality of guide vanes configured to direct aflow of fluid from the at least one of the first heat exchanger manifoldand the second heat exchanger manifold to respective passages of theplurality of columnar passages.

In another embodiment, a heat exchanger includes a heat exchanger bodythat includes a first heat exchanger manifold, a second heat exchangermanifold, a plurality of working fluid passages extending along aserpentine path between the first heat exchanger manifold and the secondheat exchanger manifold, and a plurality of coolant fluid passagesextending along the serpentine path in thermal conduction contact withthe plurality of working fluid passages. The first heat exchangermanifold, the second heat exchanger manifold, the plurality of workingfluid passages, and the plurality of coolant fluid passages are formedmonolithically of a sintered material.

Optionally, the serpentine path comprises at least one of a simplearcuate path, a complex arcuate path, a zig-zag path, an undulatingpath, a straight path, a linear path, and combinations thereof Alsooptionally, the first heat exchanger manifold includes a working fluidinlet header and a coolant fluid outlet header, wherein the second heatexchanger manifold may include a working fluid outlet header and acoolant fluid inlet header. Also optionally, the first heat exchangermanifold includes a working fluid inlet header and a working fluidoutlet header and the second heat exchanger manifold includes a coolantfluid outlet header and a coolant fluid inlet header. Optionally, afirst header member is formed monolithically with the heat exchangerbody, the first header member includes a first opening, a secondopening, and a working fluid plenum extending therebetween, and thefirst header member includes a third opening, a fourth opening, and acoolant fluid plenum extending therebetween. Also optionally, the heatexchanger includes a second header member formed monolithically with theheat exchanger body, the second header member includes a first opening,a second opening, and a working fluid plenum extending therebetween, andthe second header member includes a third opening, a fourth opening, anda coolant fluid plenum extending therebetween. The first heat exchangermanifold, the second heat exchanger manifold, the plurality of workingfluid passages, and the plurality of coolant fluid passages may beformed together seallessly. Optionally, at least one of the first heatexchanger manifold and second heat exchanger manifold comprises a flangemonolithically formed with the at least one of the first heat exchangermanifold and second heat exchanger manifold.

In yet another embodiment, a heat exchanger includes a heat exchangerbody that includes a first heat exchanger manifold including amonolithically formed flange, a second heat exchanger manifold includinga monolithically formed flange, and a plurality of sidewalls extendingalong an at least partially arcuate path between the first heatexchanger manifold and the second heat exchanger manifold. The pluralityof sidewalls are separated by a flow gap forming a plurality of workingfluid passages alternating with a plurality of coolant fluid passages inthermal conduction communication with the plurality of working fluidpassages. The first heat exchanger manifold, the second heat exchangermanifold, and the plurality of sidewalls are monolithically formed of asintered material.

Optionally, the sintered material includes any of an elemental metal, ametal alloy, a ceramic, a plastic, and any combination thereof. Alsooptionally, the sintered material includes at least one of a sinteredstructure and a partial sintered structure. The first heat exchangermanifold and flange, the second heat exchanger manifold and flange, theplurality of working fluid passages, and the plurality of coolant fluidpassages may be formed together seallessly. At least one of theplurality of sidewalls may comprise a plurality of surface features thatincrease heat transfer between the plurality of working fluid passagesand the plurality of coolant fluid passages through at least one of flowmixing, turbulation, and fin effect. At least one of the plurality ofsidewalls may include a plurality of surface features that extend intothe flow gap, and the plurality of surface features may be formed of atleast one of a plurality of flow guides, a plurality of dimples, aplurality of bumps, and a plurality of spikes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-8 show example embodiments of the apparatus described herein.

FIG. 1 is a schematic cross-sectional view of a gas turbine engine inaccordance with an exemplary embodiment of the present disclosure.

FIG. 2 is a perspective view of the heat exchanger shown in FIG. 1having a heat exchanger body.

FIG. 3 is a partial cutaway view of the heat exchanger shown in FIG. 1.

FIG. 4 is a cutaway view of the internal passages of the second heatexchanger manifold shown in FIG. 2.

FIG. 5 is an enlarged cutaway view of the internal passages of secondheat exchanger manifold shown in FIG. 2.

FIG. 6 is a perspective view of another embodiment of a heat exchangerhaving a heat exchanger body.

FIG. 7 is a cutaway view of the heat exchanger (shown in FIG. 6) takenalong line 7-7.

FIG. 8 is a cutaway view of a first manifold of the heat exchanger shownin FIG. 6.

Although specific features of various embodiments may be shown in somedrawings and not in others, this is for convenience only. Any feature ofany drawing may be referenced and/or claimed in combination with anyfeature of any other drawing.

Unless otherwise indicated, the drawings provided herein are meant toillustrate features of embodiments of the disclosure. These features arebelieved to be applicable in a wide variety of systems comprising one ormore embodiments of the disclosure. As such, the drawings are not meantto include all conventional features known by those of ordinary skill inthe art to be required for the practice of the embodiments disclosedherein.

DETAILED DESCRIPTION

The following detailed description illustrates embodiments of thedisclosure by way of example and not by way of limitation. It iscontemplated that the disclosure has general application to variousembodiments of manufacturing and operating a monolithically formedsealless heat exchanger suitable for use in industrial, commercial, andresidential applications. As used herein, “monolithically formed” refersto components or structures that are formed or cast as a single piece.

Embodiments of a heat exchanger system are described herein. The heatexchanger system is embodied in a monolithically formed heat exchangerthat may be configured with a header/manifold for supplying and/orreturning at least two different fluid streams to a patterned channelarrangement. A set of parallel contoured walls separate the fluidstreams, provide structural integrity and increase surface area for heatexchange. Monolithically formed guide vanes carry flow to and from themonolithic channel arrangement. The single piece design eliminates theneed of sealing separate parts or components through welding, brazing orbolting.

The monolithically formed heat exchanger design allows heat exchangebetween at least two fluid streams while increasing the surface areaexposed between the fluid streams. The contoured walls increase surfacearea while providing structural integrity to the monolithically formedheat exchanger. The guide vanes direct the fluid streams into and out ofthe contoured wall arrangement and may be spaced to improve the pressurevessel capability of the unit to handle pressure differentials. The heatexchanger design allows heat exchange while preventing mixing of thedistinct fluid streams.

A patterned, checkered or staggered arrangement of channels is a compactand efficient way to allow two or more fluid streams to exchange heat.The heat exchanger described herein is configurable as a header/manifoldto allow supply or extraction of at least two fluid streams from apatterned channel arrangement. The monolithically formed contoured wallsconform to the perimeter of the channel arrangement pattern to, in someembodiments, optimize package size and maximize surface area for heatexchange.

Monolithically formed guide vanes are a multi-functional design feature.They carry flow into and out of the patterned channel array, maximizesurface area for heat exchange, provide structural strength and pressurevessel capability to the contoured walls and provide support for ease ofmanufacturing of the monolithically formed heat exchanger.

The heat exchanger described herein permits the supply and theextraction of at least two different fluid streams from a patternedchannel arrangement in a monolithically formed design. Prior artrequires the use of separate parallel plates and multiple pieces such asorifice plates to allow supply and extraction from heat exchangerstructures. Separate plates need to be sealed by welding, brazing or byincorporating bolted and sealed flanges. A risk for leakage leading tomixing of the fluids is reduced by the use of monolithically formedstructures. A risk for seal wear or misassembly is eliminated onmonolithically formed designs. Heat exchanger packaging is optimized byan increase of the total surface area available for heat exchangethrough the use of monolithically formed contoured walls.

The following description refers to the accompanying drawings, in which,in the absence of a contrary representation, the same numbers indifferent drawings represent similar elements.

FIG. 1 is a schematic cross-sectional view of a gas turbine engine inaccordance with an exemplary embodiment of the present disclosure. Inthe exemplary embodiment, the gas turbine engine is embodied as ahigh-bypass gas turbine engine 110. As shown in FIG. 1, gas turbineengine 110 defines an axial direction A (extending parallel to alongitudinal centerline 112 provided for reference) and a radialdirection R (extending perpendicular to longitudinal centerline 112). Ingeneral, gas turbine engine 110 includes a fan case assembly 114 and agas turbine engine core 116 disposed downstream from fan case assembly114.

Gas turbine engine core 116 includes an approximately cylindrical ortubular outer casing 118 that defines an annular inlet 120. Outer casing118 encases, in a serial flow relationship, a compressor sectionincluding a booster or low pressure (LP) compressor 122 and a highpressure (HP) compressor 124; a combustion section 126; a turbinesection including a high pressure (HP) turbine 128 and a low pressure(LP) turbine 130; and an exhaust nozzle section 132. A high pressure(HP) spool or shaft 134 drivingly connects HP turbine 128 to HPcompressor 124. A low pressure (LP) spool or shaft 136 drivinglyconnects LP turbine 130 to LP compressor 122. Each shaft 134 and 136 issupported by a plurality of bearing assemblies 138 coupled in flowcommunication to a heat exchanger 140 configured to receive a flow ofoil from plurality of bearing assemblies 138, to cool the oil using forexample, fuel, and to return the oil to the plurality of bearingassemblies 138. LP compressor 122, HP compressor 124, combustion section126, HP turbine 128, LP turbine 130, and exhaust nozzle section 132together define a core air flow path 137.

In the exemplary embodiment, fan case assembly 114 includes a fan 142having a plurality of fan blades 144 coupled to a disk 146 in a spacedapart manner. As depicted, fan blades 144 extend outwardly from disk 146generally along radial direction R. Fan blades 144 and disk 146 aretogether rotatable about longitudinal centerline 112 by LP shaft 136.

Referring still to the exemplary embodiment of FIG. 1, disk 146 iscovered by rotatable front hub 148 aerodynamically contoured to promotean airflow through plurality of fan blades 144. Additionally, exemplaryfan case assembly 114 includes an annular fan casing or outer nacelle150 that circumferentially surrounds fan 142 and/or at least a portionof gas turbine engine core 116. It should be appreciated that outernacelle 150 may be configured to be supported relative to gas turbineengine core 116 by an outlet guide vane assembly 152. Moreover, adownstream section 154 of outer nacelle 150 may extend over an outerportion of gas turbine engine core 116 so as to define a bypass airflowpassage 156 therebetween.

During operation of gas turbine engine 110, a volume of air 158 entersgas turbine engine 110 through an associated inlet 160 of outer nacelle150 and/or fan case assembly 114. As air 158 passes across fan blades144, a first portion 162 of air 158 is directed or routed into bypassairflow passage 156 and a second portion 164 of air 158 is directed orrouted into core air flow path 137, or more specifically into LPcompressor 122. The ratio between first portion 162 of air 158 andsecond portion 164 of air 158 is commonly known as a bypass ratio. Thepressure of second portion 164 of air 158 is then increased as it isrouted through HP compressor 124 and into combustion section 126, whereit is mixed with fuel and burned to provide combustion gases 166.

Combustion gases 166 are routed through HP turbine 128 where a portionof thermal and/or kinetic energy from combustion gases 166 is extractedvia sequential stages of HP turbine stator vanes 168 that are coupled toouter casing 118 and HP turbine rotor blades 170 that are coupled to HPspool or shaft 134, thus causing HP spool or shaft 134 to rotate,thereby supporting operation of HP compressor 124. Combustion gases 166are then routed through LP turbine 130 where a second portion of thermaland kinetic energy is extracted from combustion gases 166 via sequentialstages of LP turbine stator vanes 172 that are coupled to outer casing118 and LP turbine rotor blades 174 that are coupled to LP spool orshaft 136, thus causing LP spool or shaft 136 to rotate, therebysupporting operation of LP compressor 122 and/or rotation of fan 142.Combustion gases 166 are subsequently routed through exhaust nozzlesection 132 of gas turbine engine core 116 to provide propulsive thrust.Simultaneously, the pressure of first portion 162 of air 158 isincreased as first portion 162 of air 158 is routed through bypassairflow passage 156, including through outlet guide vane assembly 152before it is exhausted from a fan nozzle exhaust section 176 of gasturbine engine 110, also providing propulsive thrust. HP turbine 128, LPturbine 130, and exhaust nozzle section 132 at least partially define ahot gas path 178 for routing combustion gases 166 through gas turbineengine core 116.

In some embodiments, gas turbine engine 110 includes a pitch changemechanism 180, and a pitch of fan blades 144 may be varied about a pitchaxis P using pitch change mechanism 180. Gas turbine engine 110 may alsoinclude one or more gearboxes 182. In such instances, when thesecomponents are present they may also be coupled in flow communicationwith heat exchanger 140, which also provides cooling for oil flowsthrough pitch change mechanism 180 and/or one or more gearboxes 182.

It should be appreciated, however, that exemplary gas turbine engine 110depicted in FIG. 1 is by way of example only, and that in otherexemplary embodiments, gas turbine engine 110 may have any othersuitable configuration. It should also be appreciated, that in stillother exemplary embodiments, aspects of the present disclosure may beincorporated into any other suitable gas turbine engine. For example, inother exemplary embodiments, aspects of the present disclosure may beincorporated into, for example, a turboprop engine, a military purposeengine, a core engine, an auxiliary power unit, a test rig, and a marineor land-based aero-derivative engine.

FIG. 2 is a perspective view of heat exchanger 140 having a heatexchanger body 202. In the example embodiment, heat exchanger 140includes a first heat exchanger manifold 204 and a second heat exchangermanifold 206. Heat exchanger 140 also includes a heat exchanger core 208extending between first heat exchanger manifold 204 and second heatexchanger manifold 206. In various embodiments, heat exchanger core 208includes a plurality of columnar passages extending between an inletplenum of heat exchanger core 208 and an outlet plenum of heat exchangercore 208. In some embodiments, the columnar passages are formed viamanufacturing methods using layer-by-layer construction or additivefabrication including, but not limited to, Selective Laser Sintering(SLS), 3D printing, such as by inkjets and laserjets, Sterolithography(SLS), Direct Selective Laser Sintering (DSLS), Electron Beam Sintering(EBS), Electron Beam Melting (EBM), Laser Engineered Net Shaping (LENS),Laser Net Shape Manufacturing (LNSM), Direct Metal Deposition (DMD), andthe like. A plurality of working fluid passages extends along aserpentine path between first heat exchanger manifold 204 and secondheat exchanger manifold 206. Although shown in FIG. 2 as having aserpentine shape, heat exchanger core 208 can also be shaped in a simplearcuate path, a complex arcuate path, a zig-zag path, an undulatingpath, a straight path, a linear path, or any other shape path thatfacilitates heat exchanger 140 in performing the functions describedherein.

A transition member is formed on each end of first heat exchangermanifold 204 and second heat exchanger manifold 206. A first transitionmember 210, a second transition member 212, a third transition member214, and a fourth transition member 216 all channel flows into or out ofa respective one of first heat exchanger manifold 204 and second heatexchanger manifold 206. Second transition member 212 and fourthtransition member 216 are formed with a respective connecting flange218, 220 configured to couple to a component or piping.

In various embodiments, first heat exchanger manifold 204 includes afirst header 222 that extends between heat exchanger core 208 and firsttransition member 210. First heat exchanger manifold 204 also includes asecond header 224 that extends between heat exchanger core 208 andsecond transition member 212. Second heat exchanger manifold 206includes a third header 226 that extends between heat exchanger core 208and third transition member 214. Second heat exchanger manifold 206 alsoincludes a fourth header 228 that extends between heat exchanger core208 and fourth transition member 216. Headers 222, 224, 226, and 228 areconfigured to channel respective flows of coolant or working fluidbetween heat exchanger core 208 and first transition member 210, secondtransition member 212, third transition member 214, and fourthtransition member 216, respectively.

FIG. 3 is a partial cutaway view of heat exchanger 140 (shown in FIG.1). FIG. 4 is a cutaway view of the internal passages of second heatexchanger manifold 206. In the example embodiment, the cutaway view ofFIG. 4 is looking into second heat exchanger manifold 206 from heatexchanger core 208. With reference to FIGS. 3 and 4, in the exampleembodiment, second heat exchanger manifold 206 includes a plurality ofmajor stiffeners 302 and a plurality of minor stiffeners 304 that alsofunction as flow guides channeling working fluid, such as oil fromplurality of bearing assemblies 138 (shown in FIG. 1), or coolant fluid,such as fuel routed for cooling purposes, from a plurality of core flowpassages 306 in heat exchanger core 208 through second heat exchangermanifold 206 and into third transition member 214. In the exampleembodiment, plurality of major stiffeners 302 and plurality of minorstiffeners 304 are formed monolithically with second heat exchangermanifold 206 and third transition member 214 by, for example, anadditive manufacturing process. In various embodiments, second heatexchanger manifold 206 and fourth transition member 216 also havesimilarly formed stiffeners 308 that also function as flow guides.Although not shown in FIG. 3, first heat exchanger manifold 204 andfirst transition member 210, and first heat exchanger manifold 204 andsecond transition member 212 also have similarly formed stiffeners thatalso function as flow guides. A plurality of manifold flow passages 310extend plurality of core flow passages 306 into second heat exchangermanifold 206.

Core flow passages 306 are divided into a first set 312 of core flowpassages 306 and into a second set 314 of core flow passages 306. In oneembodiment, first set 312 of core flow passages 306 are configured as aplurality of coolant fluid passages and second set 314 of core flowpassages 306 are configured as a plurality of working fluid passages. Inother embodiments, first set 312 of core flow passages 306 areconfigured as a plurality of working fluid passages and second set 314of core flow passages 306 are configured as a plurality of coolant fluidpassages. Core flow passages 306 are configured as a plurality ofcoolant fluid passages that extend along the path of heat exchanger core208 in thermal conduction communication with core flow passages 306configured as a plurality of working fluid passages. Additionally, firstset 312 of core flow passages 306 and second set 314 of core flowpassages 306 may be arranged as counter-flow or opposed flow or may bearranged as parallel flow. As used herein, counter-flow or opposed flowrefers to flow through adjacent first set 312 of core flow passages 306and second set 314 of core flow passages 306 being in oppositedirections. Parallel flow refers to flow through adjacent first set 312of core flow passages 306 and second set 314 of core flow passages 306being in the same direction. A height 402 of core flow passages 306 issignificantly greater than a width 404 of core flow passages 306. In oneembodiment, height 402 of core flow passages 306 is approximately tentimes greater than width 404. In another embodiment, height 402 of coreflow passages 306 is approximately twenty times greater than width 404.In still other embodiments, height 402 of core flow passages 306 isapproximately forty times greater than width 404. The greater heightthan width of core flow passages 306 increases a surface area of heattransfer surfaces between adjacent core flow passages 306. In variousembodiments, first set 312 of core flow passages 306 and second set 314of core flow passages 306 have individual core flow passages 306 thatare sized differently than remaining core flow passages 306 of first set312 of core flow passages 306 and second set 314 of core flow passages306.

In the example embodiment, first heat exchanger manifold 204, secondheat exchanger manifold 206, first set 312 of core flow passages 306 andsecond set 314 of core flow passages 306 are formed monolithically of asintered material in an additive manufacturing process. As used herein,“additive manufacturing” refers to any process which results in athree-dimensional object and includes a step of sequentially forming theshape of the object one layer at a time. Additive manufacturingprocesses include, for example, three dimensional printing,laser-net-shape manufacturing, direct metal laser sintering (DMLS),direct metal laser melting (DMLM), selective laser sintering (SLS),plasma transferred arc, freeform fabrication, and the like. Oneexemplary type of additive manufacturing process uses a laser beam tosinter or melt a powder material. Additive manufacturing processes canemploy powder materials or wire as a raw material. Moreover, additivemanufacturing processes can generally relate to a rapid way tomanufacture an object (article, component, part, product, etc.) where aplurality of thin unit layers are sequentially formed to produce theobject. For example, layers of a powder material may be provided (e.g.,laid down) and irradiated with an energy beam (e.g., laser beam) so thatthe particles of the powder material within each layer are sequentiallysintered (fused) or melted to solidify the layer. As used herein,sintered material comprises a sintered structure or a partial sinteredstructure. In various embodiments, the sintered material comprises anyof an elemental metal, a metal alloy, a ceramic, a plastic, and anycombination thereof

FIG. 5 is an enlarged cutaway view of the internal passages of secondheat exchanger manifold 206. In the example embodiment, first set 312 ofcore flow passages 306 and second set 314 of core flow passages 306 areseparated by a plurality of core passage walls 502. In the exampleembodiment, each plurality of core passage walls 502 is corrugated orhas an undulating cross-section. In other embodiments, plurality of corepassage walls 502 are flat. In still other embodiments, plurality ofcore passage walls 502 have surface features that facilitate increasingheat transfer between first set 312 of core flow passages 306 and secondset 314 of core flow passages 306 through at least one of flow mixing,turbulation, and fin effect. The surface features may be embodied in,for example, but not limited to a plurality of flow guides 504, aplurality of dimples 506, a plurality of bumps 508, and a plurality ofspikes 510.

FIG. 6 is a perspective view of another embodiment of a heat exchanger600 having a heat exchanger body 602. In the example embodiment, heatexchanger 600 includes a first heat exchanger manifold 604 and a secondheat exchanger manifold 606. Heat exchanger 600 also includes a heatexchanger core 608 extending between first heat exchanger manifold 604and second heat exchanger manifold 606. In FIG. 6, heat exchanger core608 is shaped in a simple arcuate path forming a portion of a circularpath between first heat exchanger manifold 604 and second heat exchangermanifold 606. In other embodiments, heat exchanger core 608 is formed inother shapes, such as, but not limited to a complex arcuate shape, orany other shape that facilitates heat exchanger 600 in performing thefunctions described herein.

A transition member is formed on each end of first heat exchangermanifold 604 and second heat exchanger manifold 606. A first transitionmember 610, a second transition member 612, a third transition member614, and a fourth transition member 616 all channel flows into or out ofa respective one of first heat exchanger manifold 604 and second heatexchanger manifold 606. A first connecting pipe 618 is coupled to orformed with first transition member 610. A second connecting pipe 620 iscoupled to or formed with second transition member 612. A thirdconnecting pipe 622 is coupled to or formed with third transition member614, and a fourth connecting pipe 624 is coupled to or formed withfourth transition member 616. Second connecting pipe 620 and fourthconnecting pipe 624 are formed with a respective connecting flange 626,628 that are coupled to or formed with second connecting pipe 620 andfourth connecting pipe 624 respectively, and are configured to couple toa component or piping. In the example embodiment of a cross-flow oropposed-flow heat exchanger configuration, a flow of a first fluid 630,632 enters heat exchanger 600 through second connecting pipe 620 andexits heat exchanger 600 through first connecting pipe 618. A flow of asecond fluid 634, 636 enters heat exchanger 600 through third connectingpipe 622 and exits heat exchanger 600 through fourth connecting pipe624. Heat exchanger 600 may, in other embodiments, be configured in aparallel flow configuration. In the parallel flow configuration, adirection of flow of one of flow of first fluid 630, 632 and flow ofsecond fluid 634, 636 are reversed.

FIG. 7 is a cutaway view of heat exchanger 600 taken along line 7-7(shown in FIG. 6). In the example embodiment, a first set of a pluralityof core flow passages 702 and a second set of a plurality of core flowpassages 704 alternate adjacent to one another from an outer radialperiphery 706 to an inner radial periphery 708 of heat exchanger 600.First set of plurality of core flow passages 702 and second set ofplurality of core flow passages 704 are formed of columnar sidewalls 710simultaneously and seallessly in an additive manufacturing process.Accordingly, the physical structure of columnar sidewalls 710 isindicative of a sintered or a full melt additive manufacturing process.In various embodiments, columnar sidewalls 710 have a surface contour orsurface features, similar to bumps, spikes, etc. shown in FIG. 5, thatincrease a strength of columnar sidewalls 710, increase a surface areaof columnar sidewalls 710, and/or reduce laminar flow through the firstset of the plurality of core flow passages 702 and the second set of theplurality of core flow passages 704.

FIG. 8 is a cutaway view of a first manifold 802 of heat exchanger 600(shown in FIG. 6). With reference to FIGS. 6-8, in the exampleembodiment, first manifold 802 may also be referred to as “lower”manifold 802 because of the orientation of heat exchanger 600 as shownin FIGS. 6-8. However, heat exchanger 600 may be used in a plurality ofdifferent orientations, including orientations where first manifold 802is positioned higher than the rest of heat exchanger 600. In the exampleembodiment, second connecting pipe 620 is configured to receive a flowof fluid, for example, flow of first fluid 630, 632 and channel flow offirst fluid 630, 632 into second transition member 612 where a pluralityof major guide vanes 804 channel flow of first fluid 630, 632 in acircumferential direction C. Flow of first fluid 630, 632 is furtherdirected to a plurality of minor guide vanes 806 that facilitatedirecting flow of first fluid 630, 632 into one of the first set of theplurality of core flow passages 702 and the second set of the pluralityof core flow passages 704 and facilitate turning flow of first fluid630, 632 in axial direction A into heat exchanger core 608.

Additionally, plurality of major guide vanes 804 and plurality of minorguide vanes 806 also provide additional structural integrity for heatexchanger 600 and heat exchanger core 608. Plurality of major guidevanes 804 and plurality of minor guide vanes 806 provide a stiffness orrigidity that permits operating the first set of the plurality of coreflow passages 702 and the second set of the plurality of core flowpassages 704 at significantly different pressures without bowingcomponents out of plane. Plurality of major guide vanes 804 andplurality of minor guide vanes 806 also provide a reduction in apressure drop of through the first set of the plurality of core flowpassages 702 and the second set of the plurality of core flow passages704 by facilitating turning, for example, flow of first fluid 630, 632through a sharp 90° bend in second transition member 612. Plurality ofmajor guide vanes 804 and plurality of minor guide vanes 806 allow flowof first fluid 630, 632 to turn into heat exchanger core 608 in a moreefficient way that reduces a loss coefficient of flow of first fluid630, 632 coming onboard heat exchanger core 608. Plurality of majorguide vanes 804 and plurality of minor guide vanes 806 also facilitatethe additive manufacturing process. In one embodiment, a recoater bladedeposits and removes powder from the bed of the additive manufacturingmachine. The action of the recoater blade during the forming of heatexchanger applies a lateral force to the structure being built up.Structures that are too thin may not be able to withstand the forceapplied and may collapse during the additive manufacturing process.Plurality of major guide vanes 804 and plurality of minor guide vanes806 provide additional support and permit forming heat exchanger 600with thin and tall walls.

The first set of the plurality of core flow passages 702 and the secondset of the plurality of core flow passages 704 are curved around thecircular profile of heat exchanger core 608. As such, a length of thefirst set of the plurality of core flow passages 702 and the second setof the plurality of core flow passages 704 are relatively longer thecloser the first set of the plurality of core flow passages 702 and thesecond set of the plurality of core flow passages 704 run to outerradial periphery 706 and are relatively shorter the closer the first setof the plurality of core flow passages 702 and the second set of theplurality of core flow passages 704 run to inner radial periphery 708.The disparate lengths of the first set of the plurality of core flowpassages 702 and the second set of the plurality of core flow passages704 because the first set of the plurality of core flow passages 702 andthe second set of the plurality of core flow passages 704 are running inparallel around circular heat exchanger core 608 may cause undesiredeffects. For example, the increased length increases head loss throughthe radially outermost of the first set of the plurality of core flowpassages 702 and the second set of the plurality of core flow passages704. Increased head loss creates disparate flow across heat exchangercore 608, which could affect a heat exchange capability of the first setof the plurality of core flow passages 702 and the second set of theplurality of core flow passages 704. Such effects can be mitigated byforming those core flow passages of first set of the plurality of coreflow passages 702 and the second set of the plurality of core flowpassages 704 that are positioned towards outer radial periphery 706differently than those core flow passages of first set of the pluralityof core flow passages 702 and the second set of the plurality of coreflow passages 704 that are positioned towards inner radial periphery708.

The above-described embodiments of a monolithically formed heatexchanger describe a cost-effective and reliable means for providing asealless heat exchanger. More specifically, the methods and systemsdescribed herein facilitate forming the heat exchanger without seals orjoints between components of the heat exchanger core or the heatexchanger and inlet and outlet headers and manifolds. In addition, theabove-described methods and systems facilitate manufacturing the heatexchanger using additive manufacturing using guide vanes for strengthand stability of the heat exchanger structure during operation but, alsofor manufacturability concerns. As a result, the heat exchangersdescribed herein facilitate enhanced cooling of components in acost-effective and reliable manner.

Although specific features of various embodiments of the disclosure maybe shown in some drawings and not in others, this is for convenienceonly. In accordance with the principles of the disclosure, any featureof a drawing may be referenced and/or claimed in combination with anyfeature of any other drawing.

This written description uses examples to disclose the embodiments,including the best mode, and also to enable any person skilled in theart to practice the embodiments, including making and using any devicesor systems and performing any incorporated methods. The patentable scopeof the disclosure is defined by the claims, and may include otherexamples that occur to those skilled in the art. Such other examples areintended to be within the scope of the claims if they have structuralelements that do not differ from the literal language of the claims, orif they include equivalent structural elements with insubstantialdifferences from the literal language of the claims.

What is claimed is:
 1. A heat exchanger core comprising a plurality ofcolumnar passages extending between an inlet plenum of the heatexchanger core and an outlet plenum of the heat exchanger core, thecolumnar passages formed monolithically in a single fabrication process,each of the columnar passages being separated by core passage walls,each of the core passage walls having a cross-section with alternatingconcave and convex portions.
 2. The heat exchanger core of claim 1,wherein the core passage walls are separated by a flow gap.
 3. The heatexchanger core of claim 2, wherein at least one of the core passagewalls includes a plurality of surface features that extend into the flowgap.
 4. The heat exchanger core of claim 1, wherein the plurality ofcolumnar passages include: a first set of first passages coupled inparallel flow communication; and a second set of second passages coupledin parallel flow communication, the second set of second passagesisolated from flow communication with the first set of first passages.5. The heat exchanger core of claim 4, further including a third set ofthird passages coupled in parallel flow communication, the third set ofthird passages isolated from flow communication with the first set offirst passages and the second set of second passages.
 6. The heatexchanger core of claim 4, wherein at least one of the first set offirst passages or the second set of second passages includes individualcore flow passages that are sized differently than the remaining coreflow passages of the at least one of the first set of first passages orthe second set of second passages.
 7. The heat exchanger core of claim4, wherein the first set of first passages and the second set of secondpassages are coupled in thermal conductive communication with each otheralong a length of the first set of first passages and the second set ofsecond passages between the inlet plenum of the heat exchanger core andthe outlet plenum of the heat exchanger core.
 8. The heat exchanger coreof claim 1, wherein the plurality of columnar passages includes aplurality of flow guides.
 9. The heat exchanger core of claim 1, whereinthe plurality of columnar passages includes at least one of a pluralityof dimples, a plurality of bumps, or a plurality of spikes.
 10. The heatexchanger core of claim 1, further including a first heat exchangermanifold and a second heat exchanger manifold, a transition memberformed on each end of at least one of the first heat exchanger manifoldor the second heat exchanger manifold, the transition member including aplurality of guide vanes configured to direct a flow of fluid from theat least one of the first heat exchanger manifold and the second heatexchanger manifold to respective passages of the plurality of columnarpassages of the heat exchanger core.
 11. A heat exchanger comprising aheat exchanger body, the heat exchanger body including: a first heatexchanger manifold; a second heat exchanger manifold; a serpentine heatexchanger core between the first heat exchanger manifold and the secondheat exchanger manifold, the serpentine heat exchanger core having aplurality of working fluid passages extending along a serpentine pathcreated by the serpentine heat exchanger core between the first heatexchanger manifold and the second heat exchanger manifold; and aplurality of coolant fluid passages extending along the serpentine pathin thermal conduction contact with the plurality of working fluidpassages, wherein the first heat exchanger manifold, the second heatexchanger manifold, the plurality of working fluid passages, and theplurality of coolant fluid passages are formed monolithically of asintered material, and wherein each of the plurality of working fluidpassages is separated by core passage walls, each of the core passagewalls having a corrugated cross-section.
 12. The heat exchanger of claim11, wherein the serpentine path includes at least one of a simplearcuate path, a complex arcuate path, a zig-zag path, an undulatingpath, a straight path, or a linear path.
 13. The heat exchanger of claim11, wherein the first heat exchanger manifold includes a working fluidinlet header and a coolant fluid outlet header, and wherein the secondheat exchanger manifold includes a working fluid outlet header and acoolant fluid inlet header.
 14. The heat exchanger of claim 11, whereinthe first heat exchanger manifold includes a working fluid inlet headerand a working fluid outlet header, and wherein the second heat exchangermanifold includes a coolant fluid outlet header and a coolant fluidinlet header.
 15. The heat exchanger of claim 11, further including afirst header member formed monolithically with the heat exchanger body,the first header member including a first opening, a second opening, anda working fluid plenum extending therebetween, the first header memberincluding a third opening, a fourth opening, and a coolant fluid plenumextending therebetween.
 16. The heat exchanger of claim 11, furtherincluding a second header member formed monolithically with the heatexchanger body, the second header member including a first opening, asecond opening, and a working fluid plenum extending therebetween, thesecond header member including a third opening, a fourth opening, and acoolant fluid plenum extending therebetween.
 17. The heat exchanger ofclaim 11, wherein the first heat exchanger manifold, the second heatexchanger manifold, the plurality of working fluid passages, and theplurality of coolant fluid passages are formed together seallessly. 18.The heat exchanger of claim 11, wherein at least one of the first heatexchanger manifold or the second heat exchanger manifold includes aflange monolithically formed with the at least one of the first heatexchanger manifold or the second heat exchanger manifold.
 19. The heatexchanger of claim 11, wherein the sintered material includes at leastone of a sintered structure or a partial sintered structure.
 20. Anapparatus comprising: a first heat exchanger manifold means; a secondheat exchanger manifold means; a serpentine heat exchanger core meansbetween the first heat exchanger manifold means and the second heatexchanger manifold means; and a plurality of coolant fluid passage meansextending along and in thermal conduction contact with at least aportion of the serpentine heat exchanger core means.